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Re: Radio waves...



BTW, I don't know know how a high speed modem works. How does one get a
200 - 2500 Hz bandwidth telephone channel to carry 28.8, 33.6, or 57.6 kbps
without violating Shannon's theorem? Does anyone want to tackle this
question?

David Bowman
dbowman@gtc.georgetown.ky.us

Those data rates don't seem to present a problem; Shannon says the
limiting bit rate is B*log_2(1+S/N)
Taking a bandwidth B=3000 and a S/N level of 56 db (S/N=10^5.6=398107)

gives 3000*Log_2(398108) = 55808 bits/sec.

A good S/N ratio will get you there!

For much more than you care to know about modems go to:

http://www.paranoia.com/~filipg/HTML/LINK/PORTS/F_MODEMS_DOC.html

Bob Sciamanda sciamanda@edinboro.edu
Dept of Physics
Edinboro Univ of PA http://www.edinboro.edu/~sciamanda/home.html